Emule Slow Download Help

I have been using emule 0.43b since it was released and running downloads at about 45kbs to 51 kbs on a 512 broadband connection, i recently got the popup for the new download so i downloaded it and used it for a few days and realised it was eating up my cpu speed and memory,so i decided to remove the new version which i did and re install 0.43b, i now have this nstalled and am sharing all the same stuff as previously but I can not get downloads to go above 15kbs, uploads are running at around 21-23kbs.